1. Field of the Invention
The present invention relates to cylinder head gaskets and more particularly to pushrod openings in such gaskets.
2. Related Art
Cylinder head gaskets are positioned between the engine block and the cylinder heads in an internal combustion engine. These gaskets seal around a plurality of cylinders in the engine block to ensure maximum compression and avoid leakage of coolant and engine oil into the cylinders. Such gaskets have openings for each of the cylinders as well as openings for accommodating the flow of engine coolant and engine oil between the engine block and the cylinder head. In many cases, cylinder head gaskets also have openings for the pushrods which are used to operate the valves in the cylinder heads.
Cylinder head gaskets today typically are formed by stacking multiple layers of steel on top of one another. The layers are held together in various ways, such as by welding, riveting or crimping.
The openings in many cylinder head gaskets are typically formed by a blanking process. This process typically provides openings with sharp edges, which may cause damage to the pushrods, either during assembly or during use.